ANDROID: build: fix build config kernel_dir

Change-Id: I88b87a9c85990b12dc8174349cfc14eddfb379d2
diff --git a/build.config.goldfish.x86 b/build.config.goldfish.x86
index 2b8a9b7..f86253f 100644
--- a/build.config.goldfish.x86
+++ b/build.config.goldfish.x86
@@ -3,7 +3,7 @@
 CROSS_COMPILE=x86_64-linux-android-
 DEFCONFIG=i386_ranchu_defconfig
 EXTRA_CMDS=''
-KERNEL_DIR=goldfish
+KERNEL_DIR=common
 LINUX_GCC_CROSS_COMPILE_PREBUILTS_BIN=prebuilts/gcc/linux-x86/x86/x86_64-linux-android-4.9/bin
 FILES="
 arch/x86/boot/bzImage